This invention relates to a composition, method, and apparatus for inflating and sealing inflatable objects. More particularly, the invention relates to a tire sealing and inflating composition, and a method and apparatus for using such compositions.
Portable tire sealing and inflating devices have been used in emergency by a motorist to inflate and temporarily seal a pneumatic tire with a puncture wound when a service station or other repair facilities is not available to the motorist. The use of such devices, typically for an automobile, allows the motorist to drive the vehicle to a convenient location where the punctured or flat tire can be inspected and repaired. The availability of such devices obviates the need for the motorist to remove the flat tire from an automobile and replace it with a spare tire in order to reach a service station to repair the damaged tire. More importantly, such portable devices are extremely desirable if the motorist is stranded in a dangerous situation or if the motorist either does not have a spare tire or is physically unable to replace the flat tire with a spare tire.
Generally, a portable tire sealing and inflating device includes a conventional aerosol can containing a particular sealant composition which is introduced to the cavity of a flat tire through a valve stem. Typically, a length of flexible tubing connects a valve on the can with a threaded nozzle and connector on the remote end for attachment to and activation of the valve stem. Alternatively, the can is supplied with a pedestal valve for activation and dispensing of the contents without flexible tubing. A propellant within the can forces the sealant composition through the opened valve and into the tire. In this way, the tire is inflated and sealed.
At present time, most available portable tire sealing and inflating devices are based on aerosol, which is formed by a sealant composition and a propellant. Various hydrocarbons and chlorofluorocarbons have been used as propellants. However, hydrocarbon propellants are extremely flammable, and the chlorofluorocarbon (CFC) propellants have been found to have a detrimental effect on the earth""s ozone layer and use thereof has been severely limited. Although some modified chlorofluorocarbons may not have substantial ozone-depleting potential, they may pose other environmental problems. For example, 1, 1, 2, 2-tetrafluroethane has been used as a non-flammable propellant. While not having stratospheric ozone-depletion potential, this extremely stable gas has a very significant global-warming potential (also referred to as the xe2x80x9cgreen-house effectxe2x80x9d). It is about 2,250 times as potent as carbon dioxide as a global-warming agent.
In contrast to hydrocarbons and chlorofluorocarbons, compressed gases, such as carbon dioxide, nitrous oxide, nitrogen, and air, are both environmentally-acceptable and non-flammable. However, these gases, by themselves, have not been successfully used in aerosol-based tire sealing and inflating devices. This is because relatively little of these gaseous propellants can be compressed into aerosol dispensers (regardless of the content) before the pressure exceeds 180 psig at 130xc2x0 F. (the limit imposed by the U.S. Department of Transportation for -inter-state shipping purposes). For example, if one injects nitrogen gas into the largest aerosol can (about 48.6 in3 capacity) until the pressure reaches 140 psig and connects this can to a relatively large P215/85R1 5 tire (about 2454 in3 capacity if not flattened), the tire pressure could raise from 0 psig to about 2.7 psig. As such, many cans of compressed nitrogen gas would be required to obtain a reasonable tire pressure. Consequently, using compressed gases in a tire sealing and inflating device by themselves does not appear to be a viable option.
For the foregoing reasons, there exists a need for a tire sealing and inflating device that is not based on aerosol, and that uses a non-flammable, non-toxic, and environmentally-friendly propellant.
Embodiments of the invention meet the aforementioned need in one or more of the following aspects. In one aspect, the invention relates to a tire sealing and inflating composition. The composition includes: (a) a sealant; (b) a gas-generating agent not in the gaseous state; and (c) an activator separated from the gas-generating agent before use. The activator is capable of generating a gas in situ to propel the sealant when contacted with the gas-generating agent.
In another aspect, the invention relates to a tire sealing and inflating composition. The composition includes: (1) a sealant; (2) a carbonate; and (3) an acid separated from the carbonate before use and capable of reacting with the carbonate to release carbon dioxide. The carbon dioxide is capable of propelling the sealant into an inflatable object.
In still another aspect, the invention relates to a method of inflating an inflatable object. The method includes: (a) providing a tire sealing and inflating composition having a sealant, a gas-generating agent, and an activator where the gas-generating agent is separated from the activator; (b) forming a gas propellant in situ by contacting the gas-generating agent with the activator; and (c) causing the gas to propel the sealant into an inflatable object. The inflatable object is inflated by the gas and sealed by the sealant.
In yet another aspect, the invention relates to a tire sealing and inflating device. The tire sealing and inflating device includes: (1) a first compartment having a gas-generating agent; (2) a second compartment having an activator capable of generating a gas in situ when contacted with the gas-generating agent; (3) a separator between the first and the second compartments; (4) a mixing chamber for effectuating contact between the gas-generating agent and the activator; and (5) a connector between the mixing chamber and an inflatable object.
Additional aspects of the invention and the advantages of the embodiments of the invention are apparent with the following description.